FI124816B - Process for the preparation of a product containing physically modified fat globules and a product made by the process - Google Patents

Description

Process for the preparation of a product containing physically modified globules of fat and product prepared by the process

Field of the Invention

The present invention relates to a process for the production of a fermented milk product by physical modification of a milk raw material and by an enzyme which strengthens the structure. The invention also relates to a dairy product containing fat globules of a physically modified milk raw material and treated with a cross-linking enzyme.

Background of the Invention

It is typical for the production of sour milk products to add to the homogenized heat-treated milk an acid which, when the milk is acidified, gives the product its characteristic structure and flavor.

Traditionally, all the necessary raw materials and ingredients, such as sweetener, spices and texture adjusting agents, are added to the milk and then the milk mixture is typically homogenized and acidified prior to acidification. One or two-phase homogenizers have traditionally been used for homogenization and typical homogenization conditions are 65 to 70 ° C and 150 to 200 bar pressure. The milk mixture is acidified or otherwise acidified to the specific pH of each product. Thereafter, the structure is optionally broken and cooled to the packaging temperature, the seasonings required (e.g. jam) are added and the product is packaged.

The effects of high pressure milk homogenization on particle size, water retention, syneresis, and yoghurt structure at 300 to 3500 bar have been extensively studied in recent years (Lanciotti, R. et al., Food Microbiology, 21 (2004) 753-760; Ciron, CIE et al., Int. Dairy J. 20 (2010) 314 - 320). In high pressure homogenization, high mechanical / shear forces on the milk can reduce the size of the milk fat balloons. It is known to reduce the droplet size of an emulsion by ultrasonic treatment or power ultrasonic treatment.

Basic information on the beneficial effects of high pressure homogenization of milk raw material and ultrasound technology on solidity of sour milk product such as viscosity and hardness of structure (gel) and reduction of syneresis exists. However, the problem is, in particular in the manufacture of low-fat products, the poor durability of post-treatment, such as shaping and structural breakdown.

EP 1464230 discloses desserts and fermented products from a homogenized milk-based emulsion at a pressure of 400 to 2000 bar.

US 6416797, Kraft Foods, describes a process for making a fresh cheese (Phi-ladelphia cream cheese) by adding a transglutaminase and an acid to the raw material, acidifying it to pH 4.5 and then homogenizing the acidified milk-based emulsion at high pressure (if desired). 690 bar, 10,000 psi) to modify the acidified product mass. The method described in the publication facilitates post-processing of fresh cheese, i.e. unripened cheese.

Traditionally, the structure of sour milk formulas has been used to control, e.g. increasing the dry matter content of the milk, for example by evaporation, condensation and / or powdered milk, and lowering the dry matter content. The protein content of the raw milk influences the structure of the final product and the structure of the milk product can be modified as desired by raising or lowering the protein content. For example, the protein content of yoghurt milk can be increased by evaporation or addition of protein powders such as milk, whey and casein protein powders. Protein supplements based on non-dairy proteins are also useful. Alternatively, the loosening of the structure can be accomplished by adding milk permeate, cheese whey, sour whey such as quark and / or cottage cheese whey or water to the raw milk.

The use of a cross-linking enzyme in sour milk products can also be known to harden and thicken the structure, finer structure and reduce excitation. Addition of a structural modifying cross-linking enzyme to a protein source to minimize structural problems is well known in the art. The methods traditionally use low pressure homogenized milk in the preparation of fermented milk products. The problem here is that the processes and their management are further complicated and complicated as more manufacturing steps become available. Thus, simple product compositions and cost-effective manufacturing methods are required to control the problems caused by products of the well-known processes, such as post-acidification and structural defects such as powdery structure.

In general, the problems of the known methods are the alteration of the organoleptic properties of the sourdough preparations and the poor shelf life during storage. Synthesis, awakening and structural defects occur in the products. After-treatment problems such as pulping and structural breakdown as well as storage stability problems are particularly pronounced with low-fat sour milk products.

Brief Description of the Invention

The present invention relates to a process for the production of a sour milk product by physical modification of a milk raw material and an enzyme which strengthens the structure. The invention thus provides a method of combining physical processing and treatment of fat globules with a cross-linking enzyme to prepare dairy products acidified and structured and stabilized. The method is simple, economical, large scale industrially feasible and does not entail additional costs. Further, the process according to the invention achieves significant savings when the amounts of components contained in the milk raw material, such as fat and / or protein content, can be reduced without affecting the structure and properties of the product to be manufactured. The ability to influence the amounts of the various components of the milk raw material is important because of the manufacturing of components currently used in the dairy industry. The invention also relates to a fat-containing milk product containing a physically modified milk raw material and treated with a cross-linking enzyme. The invention thus relates to optimized and post-processing steps for the various components of a milk raw material, such as pulping and structural disintegration, a highly durable fermented milk product, which also has structural properties that are resistant to storage.

It is very challenging to obtain a fully acidified milk product containing physically engineered fat globules of milk raw material that is completely flawless in taste and structure, and which undergoes both post-processing steps such as pulping and disintegration and storage of sour milk products. Controlling the content of raw material components, such as fat reduction, is challenging. Surprisingly, it was found that the acidified product of the desired structure with a significantly thicker structure was obtained by physically modifying and treating the milk raw material with a cross-linking enzyme during acidification.

By the process of the invention, the structural properties of the product to be manufactured can be improved by physically modifying the particle size, size distribution, composition and state of the fat globules of the milk raw material.

The object of the invention is achieved by a product and method which are characterized by what is stated in the independent claims. Preferred embodiments of the invention are described in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 shows a flow chart of an embodiment of a process for preparing a fermented milk product according to the invention for the production of low-fat yoghurt. In the method, fat-protein-standardized milk raw material (0.4% fat, 3.5% protein) was physically processed by high pressure homogenization at 400 bar.

Fig. 2 shows a flow chart of an embodiment of a process for preparing a fermented milk product according to the invention for the production of low-fat yogurt. In the method, the fat portion was subjected to physical high pressure homogenization at 1000 bar.

Figure 3 shows a flow chart of an embodiment of a process for preparing a fermented milk product according to the invention in the case of physical modification of the fat by microfiltration.

Detailed Description of the Invention

The invention relates to physically engineered milk fat globules, i.e. microparticles / nanoparticles of milk fat fat, and fermented milk product produced by cross-linking enzyme, and processes for making such a product. The invention enables the product to be optimized for the various components of the milk raw material while still retaining the structure and stability of the structure during storage.

Surprisingly, it was found that by physically modifying the milk raw material and treating it with a cross-linking enzyme during acidification, a sour milk product with a clear structure is compared to a similar product made from high pressure homogenized milk raw material. In addition, small fat globules produced by physical modification increase the viscosity of a sour milk product such as yoghurt, and small fat globules produced by transmembrane fatigue inhibition, crosslink small fat globules into the matrix. The proteins naturally present in the mem-bra structure of the fat globules are crosslinked. Possibly due to the presence of small fat globules with more surface and / or void volume in the structure, the caseins and whey proteins get close to each other. The crosslinking of these is then enhanced as the function of the transglutaminase is facilitated.

In addition, it was surprisingly found that the same effect is obtained by physically modifying the fat portion of the milk raw material and combining it with non-homogenized or traditionally homogenized low pressure skimmed milk and treating the milk thus obtained with a cross-linking enzyme.

Further, it has surprisingly been found that the same effect is obtained by using native and / or physically modified, e.g. skimmed milk and the milk thus obtained is treated with a cross-linking enzyme. Thus, according to one embodiment of the invention, the milk raw material is physically modified and treated with a cross-linking enzyme. According to another embodiment of the invention, the fat portion of the milk raw material is physically modified and combined with non-homogenized or traditionally low-pressure homogenized skim milk and the resulting milk raw material mixture is treated with a cross-linking enzyme. According to a third embodiment of the invention, non-homogenized or conventionally homogenized low-fat skimmed milk is combined with native and / or physically modified small fat globules and the resulting milk raw material mixture is treated with a crosslinking enzyme.

The invention also relates to a process for modifying the structure of sour milk products by physical modification of the milk raw material and a cross-linking enzyme which strengthens the structure.

Surprisingly, it has been found that by the methods of the invention, it is possible to produce either a significantly thicker sour milk product or to reduce the protein content and / or fat content of the product with the same structure structure. This means either a significant improvement in the quality of the product or significant savings in raw materials / ingredients. The methods can be applied, in particular, to the production of yoghurt, drinkable yoghurt, set-type yoghurt, filet and milk.

The processes of the invention are thus suitable for the preparation of acidified products of excellent taste and texture. In addition, the invention can help reduce the fat content of the product and / or maximize the amount of protein in the product. It is characteristic of the product according to the invention to interfere with the shaping and disintegration of the mass typical of sour milk products during manufacture and the storage of the product.

Physical modification of a milk raw material in the context of the present invention means a process of changing the particle size, size distribution, size distribution of the fat raw material of the milk raw material by means of high mechanical forces / shear forces on the milk raw material or combinations thereof.

Industrial scale mixers with energy density sufficient to provide high mechanical / shear forces that produce grease particles having a particle size of less than 10 µm are, for example, homogenizers (less than 4 pm), high pressure homogenizers (less than 2 pm), microfluidizers (less than 1 pm). , rotor-stator systems (Ultra Turrax; particle size between 1 and 25 pm) and colloidal mills (particle size between 1 and 25 pm). The size, size distribution, composition and state of the fat globules of the milk raw material can also be physically modified by extrusion, ultrasound (power ultrasound), optical technology (Laser, Light Amplification by Stimulated Emission of Radiation, HPP) high pressure treatment), atomizer (spray drying), nonthermal pulsed electric field (PEF) technology and a combination of different technologies. MTS (manothermosonication) technology combines ultrasonic treatment with a temperature lower than pasteurization temperature. Membrane techniques such as microfiltration and gravity as well as combinations of different techniques can be used as separation techniques.

According to one embodiment of the invention, the physical shaping is carried out by high pressure homogenization at 40-95 ° C, preferably 60-70 ° C, and 250-1000 bar, preferably 250-500 bar. In one embodiment of the invention, the high pressure homogenization is carried out in two steps. In another embodiment of the invention, the high pressure homogenization process is carried out in two stages such that in the first stage the temperature is between 40-95 ° C and the pressure is 250-1000 bar and in the second stage the temperature is between 40-95 ° C and the pressure below 1000 bar. In the first step, the size of the event fat globules is reduced and in the second step, any fat globules that are attached to each other are separated into separate balls. In the second step, the homogenization conditions may correspond to the conditions of high pressure homogenization or may be either conventional or even lower / lower.

According to another embodiment of the invention, the physical shaping is done by microfiltration. Microfiltration (MF) is a membrane filtration method in which the membranes used have an average pore size of 0.05 to 10 µm. By pressure, the separated components contained in the liquid are forced through the membrane.

In milk, fat is present in so-called "fat". in spheres having a diameter in the range of 0.1 to 15 µm. The average fat content of raw milk is 4.5%. About 80% of the fat globules in milk are less than 1 µm in diameter, but less than 10% of the total fat. The average fat pad is about 4 µm in diameter. Larger beads (greater than 2 pm) have been found to accumulate more readily than small beads (less than 2 pm) and are more susceptible to lipolysis. Large beads also bind less water.

By microfiltration, native fat globules divided into different size classes lose their original membrane structure, as occurs, for example, when homogenizing. Homogenization under pressure affects the fat globules in such a way that it disintegrates large fat globules into smaller portions, replacing part of the membrane membrane with casein proteins. This changes the properties of the fat globules, e.g. such that they are less susceptible to, for example, fat oxidative spoilage effects. Fat spheres reduced by homogenization and casein-coated behave in a manner similar to casein.

According to another embodiment of the invention, physical shaping is performed by high pressure homogenization and microfiltration in either order. In this embodiment, for example, the milk raw material may first be microfiltrated, followed by high pressure homogenization of the microfiltration-derived retentate and combined with the microfiltration permeate for further processing.

In this application, the term "physical modification of a milk raw material" is intended to encompass, in addition to the above methods, the modification by enzymes (fat-acting enzymes, phospholipases, lipases, etc.).

The terms 'mechanically modified fat globules', 'physically modified fat globules', 'microparticles', 'nanoparticles' and 'enzymatically modified fat globules' are used interchangeably.

In addition, the terms 'milk fat fat globule' and 'milk fat fat microparticle / nanoparticle' are used interchangeably. The term "milk globule fat globules" refers to microparticles and / or nanoparticles or fatty acid chains or portions separated from fat globules of milk raw material fat.

According to one embodiment of the invention, the size of the fat globules resulting from physical modification is between 100 nm and 4 pm, more preferably between 2 pm and more preferably between 100 nm and 2 pm. According to another embodiment of the invention, the average particle size, i.e. average size, of the fat globules obtained by physical modification is between 0.6 µm and 1.5 µm, preferably between about 1 µm and more preferably between 0.6 µm and 1 µm. According to another embodiment of the invention, the size of the fat globules obtained by physical modification is between 100 nm and 4 µm, preferably less than 2 µm and more preferably between 100 nm and 2 µm and the average particle size, i.e. average size between 0.6 µm and 1.5 µm, preferably less than about 1 µm. pm and more preferably between 0.6 pm and 1 pm.

The milk raw material may be milk, whey and milk and whey combinations as such or in concentrated form. The milk raw material may be derived from a cow, sheep, goat, camel, oak or other milk-producing animal fit for human consumption, either as such or in the form of a desired pre-treatment. The milk raw material may be, for example, whole milk, cream, skimmed or skimmed milk, low-lactose or lactose-free milk, colostrum, ultra-filtered milk, diafiltered milk, milk impregnated with milk powder, organic milk or organic milk. According to one embodiment of the invention, the fat content of the milk raw material is between 0.4 and 2%. Preferably, the milk raw material is low fat milk (fat content 0.5 to 1.5%) standardized with cream (30 to 50%) or skim milk (1.5 to 4%) or skim milk (fat content less than 0.5%) standardized whole milk (over 4%).

The milk raw material may be supplemented with ingredients commonly used in the preparation of dairy products and / or whey and milk protein fractions such as milk protein, whey protein, casein, whey and milk protein fractions, milk salt, α-lactalbumin, peptides, amino acids, or in different combinations and in different amounts depending on the product being manufactured. The dairy raw material may be supplemented with vegetable fat such as rapeseed oil, corn oil, sunflower oil, berry oil, alone or in various combinations in varying amounts depending on the product being manufactured. Other optional ingredients / components include omega-3 fatty acids, antioxidants and / or water-soluble or fat-soluble vitamins, sterols and their esters that affect blood cholesterol levels, and saturation-enhancing compounds or compositions such as oil-in-water emulsion and maitosuolat. These optional components may be used alone or in different combinations and to varying degrees in the process of the invention, depending on the product being manufactured. Whey and milk protein fractions can be prepared, for example, by ultra or nanofiltration (NF retentate).

The present invention provides a novel solution in a method for avoiding structural and quality defects in the manufacture of sour milk products, characterized by treating the milk raw material containing physically modified fat globules with a cross-linking enzyme.

According to one embodiment of the invention, the milk raw material is physically modified and treated with a cross-linking enzyme. According to this embodiment, the milk raw material containing physically modified fat globules is obtained by physically modifying the particle size, size distribution, composition and state of the fat globules of the milk raw material. Physical modification may be effected, for example, using high pressure homogenization time and / or microfiltration. Thus, in an alternative within the scope of this embodiment, the milk raw material or portion thereof is fractionated by microfiltration and the permeate containing small fat globules is subjected to cross-linking enzyme treatment alone or in combination with a high pressure treated retentate. Between physical treatment of the milk raw material and treatment with a cross-linking enzyme, other processing steps may be performed if desired and / or necessary. Further, before the physical processing of the milk raw material, other processing steps may be performed. Similarly, after treatment with a cross-linking enzyme, further processing steps can be performed.

According to another embodiment of the invention, the fat portion of the milk raw material is physically modified and combined with non-homogenized or traditionally low-pressure homogenized skimmed milk, thereby treating the raw milk mixture with a cross-linking enzyme and acidifying. According to this embodiment, the milk raw material containing the physically modified fat globules is obtained by physically modifying the fat portion of the milk raw material and combining it with non-homogenized or traditionally homogenized skim milk. Physical modification may be effected, for example, by high pressure homogenization and / or microfiltration. In an alternative within the scope of this embodiment, the fat portion of the milk raw material is fractionated by microfiltration and the permeate containing the small fat globules is subjected to treatment with a cross-linking enzyme as such or in combination with a high pressure treated other treatment steps such as, for example, heat treatment (s) may be performed if desired and / or necessary. Further, prior to the preparation of the physically modified fat globule-containing milk raw material mixture, other processing steps generally known in the art, such as, for example, heat treatment, conditioning, regeneration, protease, filtration, separation and / or freezing, may be performed. Similarly, after treatment with a cross-linking enzyme, further processing steps can be performed.

According to a third embodiment of the invention, non-homogenized or traditionally homogenized low-fat skimmed milk is combined with native and / or physically modified small fat spheres and the resulting milk raw material mixture is treated with a cross-linked / or physically distilled skimmed-milk balls into non-homogenized or traditionally homogenized skimmed milk. In one embodiment covered by this embodiment, the size of the fat globules obtained by native and / or physical modification is between 100 nm and 4 pm, preferably less than 2 pm and more preferably between 100 nm and 2 pm. According to another embodiment of the embodiment, the average size of the native and / or physical fat globules obtained is between 0.6 µm and 1.5 µm, preferably less than about 1 µm and more preferably between 0.6 µm and 1 µm. In another alternative embodiment, the size of the fat globules obtained by native and / or physical modification is between 100 nm and 4 pm, preferably less than 2 pm and more preferably between 100 nm and 2 pm and the average size is between 0.6 pm and 1.5 pm, preferably less about 1 pm and more preferably between 0.6 pm and 1 pm.

Between the preparation of the milk raw material mixture containing the physically modified and / or native fat globules and the treatment with the cross-linking enzyme, other processing steps such as heat treatment may be carried out if desired and / or necessary. Further, prior to the preparation of a milk raw material mixture containing native and / or physically modified fat globules, other processing steps known in the art may be performed. Similarly, after treatment with a cross-linking enzyme, further processing steps can be performed.

According to one embodiment of the invention, the method for producing an acidic milk product comprises: - physically modifying the milk raw material, - treating with a cross-linking enzyme, and - acidifying, and - optionally, packaging the product.

According to another embodiment of the invention, the process for preparing the sour milk product comprises: - physically modifying the fat portion of the milk raw material and combining it with non-homogenized or traditionally low-pressure homogenized skim milk, - treating with a cross-linking enzyme and - optionally packaging.

According to another embodiment of the invention, the method for producing the sour milk product comprises: - combining native and / or physically modified fat globules into non-homogenized or traditionally homogenized low-pressure skimmed milk, - treatment with a cross-linking enzyme, - acidifying, and - optionally.

In the process of the invention, the acidification may be preceded by treatment with a cross-linking enzyme, concurrently with a cross-linking enzyme or after treatment with a cross-linking enzyme. In the process of the invention, the cross-linking enzyme may be treated concurrently with or after acidification. Thus, according to one embodiment of the invention, the process comprises the following steps: - physically modifying the particle size, size distribution, composition and state of the fat globules of the milk raw material, - acidifying, - treating with a cross-linking enzyme, - optionally packaging the product.

According to another embodiment of the invention, the process itself comprises the following steps: - physically modifying the particle size, size distribution, composition and state of the fat globules of the milk raw material, - acidifying and treating with a cross-linking enzyme, - optionally packing the product.

Furthermore, according to one embodiment of the invention, the process itself comprises the following steps: - physically modifying the particle size, size distribution, composition and state of the fat globules of the milk raw material, - treating with a cross-linking enzyme, - acidifying, - optionally packaging the product.

Further, the sour milk products made by the process of the invention may alternatively be fermented either before or immediately after packaging of the product. Of the sour milk products, in particular, single-skinned products and set-type yogurts are fermented in packaging. Thus, according to one embodiment of the invention, the process comprises the following steps: physically modifying the particle size, size distribution, composition and volume of the fat raw material of milk; acidified and treated with a cross-linking enzyme package.

In the process according to the invention, the heat treatment can also be carried out in several stages.

If necessary, the composition of the milk raw material used in the method can be adjusted by standardizing the composition of the milk raw material in terms of protein, fat and / or lactose content. The milk raw material used in the process may, if desired / necessary, be subjected to a heat treatment before or after physical processing. Thus, according to one embodiment of the invention, the process comprises the following steps: - adjusting the composition of the milk raw material, i.e., stabilizing the composition of the milk raw material with regard to protein, fat and / or lactose content, - heat treating the milk raw material; - size, size distribution, composition and state, - heat-treated, - acidified, - treated with a cross-linking enzyme, - optionally packaged.

The process may include, in addition to acidification, the use of a flux and, if necessary, a subsequent heat treatment, i.e. post-pasteurization. Thus, according to one embodiment of the invention, the process comprises the following steps: - where appropriate, stabilizing the composition of the milk raw material with respect to its protein, fat and / or lactose content, - heat treating the milk raw material if desired - physically modifying the particle size of the fat globules; composition and state, - heat treatment if necessary, - acidification, - treatment with a cross-linking enzyme, - addition of rennet or other enzymes, - heat treatment, - optionally packaging of the product obtained.

Further, the process may also include the step of addition of other raw materials after acidification and treatment with a cross-linking enzyme. Thus, according to one embodiment of the invention, the process comprises the following steps: - where appropriate, stabilizing the composition of the milk raw material in terms of protein, fat and / or lactose content, - heat treating the milk raw material if desired, physically modifying the particle size of the fat globules; , composition and condition, - heat treated if necessary, - acidified, - treated with a cross-linking enzyme, - addition of a rennet, if desired, - addition of other raw materials, - heat treatment if necessary, - optionally packing the product obtained.

According to one embodiment of the invention, the milk, raw material standardized for protein, fat and / or carbohydrate content is optionally heat treated, physically modified with particle size, size distribution, composition and state of its fat globules, and crosslinked with an enzymatic moiety. According to another embodiment of the invention, the composition of the milk raw material is controlled by constant its protein, fat and carbohydrate content, heat-treated standardized milk raw material, shaping the particle size, size distribution, composition and space homogenization of fat globules at 40-95 ° C. bar, and simultaneously modified with a cross-linking enzyme with chemical acidification.

In the process of the invention, the physical modification of the milk raw material may be performed on the milk raw material or a portion thereof in several steps by the same method or by combining different techniques to change the particle size, size distribution, composition and state of the fat globules. The physical modification of the milk raw material or a portion thereof can thus be effected, for example, by high pressure homogenization or microfiltration or by both high pressure homogenization and microfiltration. Thus, according to one embodiment of the invention, the process comprises the following steps: - physically modifying the particle size, size distribution, composition and state of the fat globules of the milk raw material or portion thereof by multiple techniques and / or steps, - heat treatment if desired, - crosslinking optionally, packaging the resulting product.

According to one embodiment of the invention, the milk raw material, which has been standardized for protein, fat and / or lactose content, is high-pressure homogenized, treated with a cross-linking enzyme, heat treated and cooled separately, if desired, high pressure homogenized and / or - 50%, preferably 35%) of the milk raw material, the acidifier is added, the pulp is mixed and packaged.

In the process of the invention, the acidification can be carried out with the addition of a biological acid specific to each product (for example, use acid or product batch acid), chemical acid or organic or inorganic acids, with or without addition of rennet. For example, strains of Lactobacillus bulgaricus and Streptococcus thermophilus are traditionally used in the production of yogurt. Examples of suitable organic acids are gluconodeltalactone (GDL), calcium lactate, citric acids, lactic acid. Preferably, the acid used is gluconodeltalactone. In addition to the lactic acid bacterial patches, file molds are used in the manufacture of file-type products.

Alternatively, the fermented products made by the process of the invention may be fermented either in the tank before or immediately after packaging in a consumer or mass-market container.

Of sour milk products, in particular, file-type products and set-type yoghurts are fermented on the packaging.

The thickness of the structure is controlled by adjusting the dosage of the cross-linking enzymes. The product may be so-called. “Set type” (cutting and spooning product), drinking (fresh), drinking UHT, spooning “yogurt” type or powder (spray-thinned powder) Nutritional proteins such as essential amino acids are highly absorbable in the product.

Amino acids of animal and plant proteins can be cross-linked with enzymes, for example, by transglutaminase (EC 2.3.2.13). The covalent bonds formed in the enzyme treatment can withstand very different process conditions such as heating and mixing. Of the milk proteins, caseins, even κ-casein, are the best substrate for transglutaminase. Β - casein is also rich in glutamine and lysine, which are linked by an enzyme. The transglutaminase used may be any transglutaminase enzyme used in the dairy industry and may be derived from a microbial, yeast, mold, fish or mammal. According to one embodiment of the invention, the transglutaminase enzyme is microbial. Several different transglutaminase enzyme preparations are commercially available which are suitable for use in the process of the invention. Examples are Activa®YG (Ajinomoto, Japan) and Activa®MP (Ajinomoto, Japan). The optimum conditions will depend on the particular enzyme and are available from commercial enzyme manufacturers.

Other possible cross-linking and protein-modifying enzymes include laccase, tyrosinase, peroxidase, sulfhydryl oxidase, glucose oxidase, protein glutaminase and generally other protein-modifying enzymes such as chymosin and proteases. Tyrosinases (EC1.14.18.1) can be derived from different species of plants, animals or fungi, such as Trichodermareese / filamentous fungi. It is known that laccases (EC 1.10.3.2) derived from fungi or bacteria, such as Tra-metes hirsuta, heterologously cross-link carbohydrates and proteins. Tyrosinase and laccase preparations are also commercially available. The optimum conditions will depend on the particular enzyme and are available from commercial enzyme manufacturers. Said enzymes may be used alone or in combination to obtain the desired end result.

The process of the invention may also include one or more further processing steps of a milk raw material containing physically modified fat globules treated with a crosslinking enzyme and acidified, for example by mixing, separating, flavoring, cooling, packaging and / or making a product dependent on the product.

In the process of the invention, the heat treatment or heat treatment is carried out as is known in the art. Examples of heat treatment methods useful in the process of the invention include pasteurisation, high pasteurization, heating at a temperature below the pasteurization temperature for a sufficient period of time, thermalization or heating for at least 15 seconds at about 57-68 ° C, UHT-HT and ESL treatments. In the UHT treatment, the raw material is heated at about 135-140 ° C for 2-4 seconds. HT-treated fshort UHT treatment ') is described in WO2010085957. In ESL treatment, the raw material is heated at about 127-135 ° C for 1-2 seconds. In pasteurisation, the raw material is heated at 70-72 ° C for at least 15 seconds, and in high pasteurization, the raw material is heated at about 95 ° C for at least 5 minutes. Heat treatment can also be performed by a combination of different techniques.

According to the invention, farm milk (unmalted and non-pasteurized milk, raw milk) which was pressurized at 400 bar and transglutaminase treated during acidification was 65-35% thicker depending on the shelf life compared to yoghurt alone at 400 bar. Also, similarly prepared milks containing 0.4% fat and 1.0% fat, which were pressurized at 400 bar and treated with transglutaminase during acidification, were 2 times thicker than the comparison that was pressurized only.

Further, the viscosity of the yogurt prepared according to the invention, pressurized at 400 bar and transglutaminase treated during acidification, was 30% thicker compared to yogurt homogenized at 200 bar and transglutaminase treated during acidification and 60% thicker. ¬ 200 bar but not treated with transglutaminase.

According to the invention, the same effect is obtained by homogenizing only the fat portion by high pressure and combining it with non-homogenized or traditionally low-pressure homogenized skimmed milk and thus processing the resulting milk with transglutaminase.

The structure of the products prepared by the process of the present invention remained homogeneous and no separation of whey occurred during cold storage (+ 4 ° C, 3 weeks) or storage at room temperature (20-25 ° C, several weeks). An example of a preferred form of the process of the invention is the production of yogurt with a protein content of 3.4 to 3.5%. The viscosity of the fatty (4.1%) yoghurt according to the invention was 30% thicker at 1 week and 65% thicker at 3 weeks. The low fat (1%) yoghurt according to the invention had a viscosity of 100% thicker throughout the 3 week shelf life compared to the reference yoghurt. Even lower fat (0.4%) yoghurt according to the invention had a viscosity of 85% at 1 day, 50% at 1-2 weeks and 30% at 3 weeks compared to comparative yoghurt.

In addition, it was surprisingly found that the same effect is obtained by homogenizing only the fat portion and combining it with non-homogenized or traditionally homogenized low pressure skimmed milk and the resulting milk is transglutaminated. An example of a preferred embodiment of the invention is the yoghurt prepared by the process described with the raw materials: The fat portion (fat 35% and protein 2%) was homogenized at 1000 bar at 60 ° C, combined with whipped cream and non-homogenized skim milk had a fat content of 1.5% and a protein of 3.5%, was pasteurized and cooled to 42 ° C, and the TG enzyme 0.6 U / g (protein) and acid was added. The pulp was allowed to acidify until pH 4.5 was stirred and cooled to 20 ° C and packaged.

The process according to the invention is simple and suitable for large-scale production.

According to one embodiment of the invention, the method is a component manufacturing method in which milk components of different fat and protein contents are combined only prior to packaging.

The process of the present invention can be applied to batch and continuous manufacturing. Preferably, the process of the invention is carried out as a batch process.

The invention also relates to physically modified milk fat fat globules, i.e., microparticles / nanoparticles containing milk fat fat and a fermented milk product produced by a cross-linking enzyme. According to one embodiment of the invention, the fat globules contained in the acidified milk-based product are between 100 nm and 4 µm in size, preferably between 2 µm and more preferably between 100 nm and 2 µm. Further, according to another embodiment of the invention, the average size of ras in the acidified milk-based product is between 0.6 µm and 1.5 µm, preferably between about 1 µm and more preferably between 0.6 µm and 1 µm. In another embodiment of the invention, the fat globules contained in the acidified milk-based product have a size between 100 nm and 4 µm, preferably less than 2 µm, more preferably between 100 nm and 2 µm, and an average size between 0.6 µm and 1.5 µm, preferably about 1 µm. pm -1 pm.

The following examples illustrate the practice of the invention but do not limit the invention to the aforementioned product applications.

Example 1

Yoghurt made from farm milk (400 bar and TG treatment)

The test yoghurt according to the invention was prepared from farm milk (fat 4.1% and protein 3.4%) which was homogenized at 60 ° C at 400 bar. The milk was then pasteurized and cooled to 42 ° C. TG enzyme (Activa®MP) 0.6 U / g (protein) and acid was added. The mixture was allowed to acidify until pH 4.5. The mass was stirred and cooled to 20 ° C and packed. The masses were then transferred to a cold room to cool to 5 ° C.

Otherwise, the control yoghurt was prepared in the same manner as the test yoghurt according to the invention except that no TG enzyme was added to the yeast.

The viscosity of the yoghurt according to the invention was 30% thicker at 1 week and 65% thicker at 3 weeks than the reference yoghurt.

Example 2 Yoghurt made from milk with 1.0% fat (400 bar and TG treatment)

The test yoghurt according to the invention was made from milk (fat 1.0% and protein 3.5%) which was homogenized at 60 ° C at 400 bar. The milk was then pasteurized and cooled to 42 ° C. TG enzyme (Activa®MP) 0.6 U / g (protein) and acid was added. The mixture was allowed to acidify until pH 4.5. The mass was stirred and cooled to 20 ° C and packed. The masses were then transferred to a cold room to cool to 5 ° C.

Otherwise, the control yoghurt was prepared in the same manner as the test yoghurt according to the invention except that no TG enzyme was added to the yeast.

The viscosity of the yoghurt according to the invention was 100% thicker throughout the 3 week shelf life compared to the reference yoghurt.

Example 3 Yoghurt made from milk containing 0.4% fat (400 bar and TG treatment)

The test yoghurt according to the invention was prepared from milk (fat 0.4% and protein 3.5%), which was homogenized at 60 ° C under pressure of 400 bar. The milk was then pasteurized and cooled to 42 ° C. TG enzyme (Activa®MP) 0.6 U / g (protein) and acid was added. The mixture was allowed to acidify until pH 4.5. The mass was stirred and cooled to 20 ° C and packed. The masses were then transferred to a cold room to cool to 5 ° C.

Otherwise, the control yoghurt was prepared in the same manner as the test yoghurt according to the invention except that no TG enzyme was added to the yeast.

The viscosity of the yoghurt according to the invention was 85% at 1 day, 50% at 1 to 2 weeks and 30% at 3 weeks compared to comparative yogurt.

Example 4 Yoghurt of the invention (400 bar with TG treatment) and comparison yoghurt 1 (200 bar) and comparative yoghurt 2 (200 bar + TG treatment) according to the invention with 0.4% fat milk

The test yoghurt according to the invention was made from milk (fat 0.4% and protein 3.5%) which was homogenized at 60 ° C at 400 bar. The milk was then pasteurized and cooled to 42 ° C. TG enzyme (Activa®MP) 0.6 U / g (protein) and acid was added. The mixture was allowed to acidify until pH 4.5. The mass was stirred and cooled to 20 ° C and packed. The masses were then transferred to a cold room to cool to 5 ° C.

Comparative yoghurt 1 was otherwise prepared in the same manner as the test yoghurt according to the invention except that no TG enzyme was added to the fermenter and the milk was homogenized at 200 bar.

Comparative yogurt 2 was otherwise prepared in the same manner as the test yoghurt of the invention except that the milk was homogenized at 200 bar.

The viscosity of the yoghurt according to the invention at the age of one week was 60% thicker than the reference yoghurt 1 and the reference yogurt 2 at the age of one week was 30% thicker than the reference yoghurt 1.

Example 5

Homogenization of the fat part separately (1000 bar) and yoghurt made from milk containing 1,5% fat (TG treatment)

The fat portion of the test yoghurt according to the invention (fat 35% and protein 2%) was homogenized at 1000 bar at 60 ° C. Thereafter, the whipped cream and the non-homogenized skimmed milk were combined so that the raw material had a fat content of 1.5% and a protein content of 3.5%. The milk was then pasteurized and cooled to 42 ° C. TG enzyme (Ac-tiva®MP) 0.6 U / g (protein) and acid was added. The mixture was allowed to acidify to pH 4.5. The mass was stirred and cooled to 20 ° C and packaged. The masses were then transferred to a cold room to cool to 5 ° C.

Otherwise, the control yoghurt was prepared in the same manner as the test yoghurt according to the invention except that no TG enzyme was added to the yeast.

The viscosity of the yoghurt according to the invention was 50% thicker at 1 day and 3 weeks compared to the reference yogurt.

Example 6

Kerman microfiltration

The cream was filtered through a Tetra Alcross MFS-1 microfiltration apparatus with a ceramic tubular filtration membrane. A pressure of about 4 bar was sought for the upper end of the feed. Permeate and retentate between the differential pressure of about 0.4 bar.

The total areas and mean particle diameters of the unfiltered crude cream and microfiltration permeate and retentate calculated by the Malvern program are shown in Table 1.

Table 1. Total areas and average particle diameters calculated using the Malvern program.

Example 7

Yoghurt made with microfiltration permeate

Three yoghurts were prepared with 2.5% fat control and in which (a) non-homogenized skimmed milk was standardized with an un homogenized cream and the resulting milk raw material mixture (2.5% fat homogenized at 140/20 bar (reference), b) milk raw material (reference) 2.5% fat) was obtained by the addition of homogeneous cream permeate obtained by microfiltration of the raw cream from homogeneous skimmed milk, and (c) milk raw material (2.5% fat content) was obtained by addition of .

It was found that in the non-homogenized standardized raw milk (c) fat was raised to the surface, whereas in the homogenized (a) or cream permeate (b) milk raw material there was no phase separation. The milk raw materials were pasteurized at 90 ° C for 5 min and acidified with yoghurt acid at 42 ° C / pH 4.5. The gelled yogurt was blended. The yoghurt, which had a homogenized fat (average particle size of about 0.5 µm), was traditionally the thickest (200-400 mPas). The texture of this yogurt still thickened during storage. The yoghurt without homogenization (average fat particle size was about 4 µm) had a thickness of about 100 mPas fresh and 200 mPas after 3 weeks of storage. With cream permeate (average fat particle size 1.8 µm), the yoghurt thicknesses were 100 and 125mPas. Yogurt with cream permeate had the most stable structure, no change in viscosity during storage. Whey was not distinguished from any sample.

Claims (16)

Process for the preparation of a sour milk product, characterized in that a milk cream material containing high-pressure homogenization processed fat particles is treated with a cross-linking enzyme and acidified. Process according to claim 1, characterized in that the milk crust material containing high-pressure homogenization processed fat particles is obtained by processing with high-pressure homogenization of the particle size, size distribution, composition and condition of the fat crust material. 3. A process according to claim 1, characterized in that the milk crust containing high-pressure homogenized processed fat particles is obtained by processing the high-homogenization fat portion of the milk cream material and by combining the non-homogenized or traditionally homogenized fat-free milk. 4. A process according to claim 1, characterized in that the milk crayon containing high-pressure homogenized processed fat particles is obtained by combining natives and / or high-pressure homogenizing processed fat particles with non-homogenized or traditional homogenized fat-free milk. Process according to any one of claims 1 to 4, characterized by reduced treatment with cross-linking enzyme before, simultaneously with or after acidification. Process according to claim 2, characterized in that the process comprises the following steps: - with high pressure homogenization, the particle size, size distribution, composition and condition of the milk cream material are processed, - acidified, - treated with crosslinking enzyme, - optionally the resulting product is packaged. Process according to claim 2, characterized in that the process comprises the following steps: - with high pressure homogenisation, the particle size, size distribution, composition and condition of the milk cream material's fat particles are processed - acidified and treated with crosslinking enzyme in a gasket. Process according to claim 6, characterized in that the process comprises the following steps: - if necessary, the composition of the milk cream material is controlled, - if desired, the milk cream material is heat treated, - with high pressure homogenization, - acidified, - treated with cross-linking enzyme, - if desired, a barrel is added, - if desired heat treated, - if desired, other raw materials are added, - optionally the product obtained is packaged. Process according to any of claims 1 to 8, characterized in that the fat particles are processed by microfiltration. Process according to any one of claims 1-9, characterized in that the acidification is carried out biologically by the addition of an acidifier or a product acidifier, a chemical acidifier, organic acids or inorganic acids combined with the addition of a barrel or without the addition of a barrel. Process according to any of the preceding claims, characterized in that, as a process, component production, in which milk components with different fat and protein content are first combined before packing. Process according to any of the preceding claims, characterized in that the manufacturing process is either continuous or batch process. Process according to any of the preceding claims, characterized in that the acidification is carried out either in a tank or before packing the product or immediately after packing in a consumer or catering kitchen package. Acidized milk-based product, characterized in that it is made by a process according to any of claims 1-13. Acidized milk-based product according to claim 14, characterized in that it contains processed fat particles with high pressure homogenization, the size of which is between 100 nm and 4 µm, preferably below 2 µm. Product according to claim 15, characterized in that the average size of the fat particles is between 0.6 and 1.5 µm, preferably about 1 µm.